Pressurized air-powered liquid sprayers, commonly referred to as spray guns, have been used for a considerable number of years for applying paint or other liquid material to a surface or object. These sprayers usually have a pistol grip handle and an outwardly extending spray barrel on which is attached a container for holding a supply of paint or other liquid. The gun is connected to a compressor or other source of pressurized air, whereby movement of a release valve will permit the air to flow through the gun and out of the discharge end thereof, drawing with it a predetermined quantity of liquid from the attached container. The air and liquid are mixed in various manners whereby the liquid particles are atomized by the pressurized air to create an evenly distributed pattern on the object being coated. Numerous types of spray nozzles have been developed for use with pressurized air spray guns for enhancing the atomization and paint pattern achieved thereby. In many of these prior art nozzles, the pressurized air streams are directed at various angles against the liquid stream as it is being discharged from the nozzle end. Examples of such prior art spray nozzles are shown in U.S. Pat. Nos. 1,990,823; 2,070,696 and 2,082,060. Examples of other known prior art spray nozzles and similar devices are disclosed in U.S. Pat. Nos. 1,661,150; 1,780,738; 2,029,423; 2,544,123; 3,685,741; 3,687,368;3,746,253; 3,876,150; 3,905,554; 4,171,091; 4,171,096; 4,343,433; 4,349,153; 4,361,285; 4,381,081; 4,385,728; 4,478,370; 4,501,394; 4,531,675; 4,544,100; 4,616,784.
One of the main purposes of these spray nozzles, as well as other prior art nozzles, is to atomize the liquid spray by directing the air against the stream of liquid. One problem is that atomization of the liquid, although providing in many instances a satisfactory spray pattern and coating, causes dried liquid particles to float in the air, which particles settle on surrounding furniture, floors, windows, etc., requiring complete coverage of the adjacent areas with cloths and other protective coverings. This atomized liquid, especially if paint, will leave small specks of paint surrounding the area being painted. Also, these prior art nozzles provide only one type of spray pattern, such as the usual relatively broad pattern for completely covering an area being coated. These prior art nozzles do not permit various spray patterns to be achieved by the same nozzle.
Another problem with existing sprayers, especially paint sprayers, is the fixed nature thereof. In order to achieve satisfactory results with these existing sprayers, the viscosity of the paint has to be adjusted to a predetermined value. This requires the use of viscosity meters and the regulation of the viscosity of the paint by the addition of thinners in order for the sprayer to function satisfactorily since existing spray nozzles do not provide any type of satisfactory adjustment means to compensate for liquids or paints of different viscosities.
The closest known prior art to my present invention is that which is disclosed in a patent application filed in the Patent and Trademark Office on Oct. 26, 1981 and assigned Ser. No. 315,259, but which was subsequently abandoned. Although the three embodiments of the spray nozzle disclosed in the abandoned application satisfy needs and solve problems existing in the art, they do not achieve the objectives and advantages obtained by the spray nozzle of the present invention.
More specifically, the liquid spray nozzle adapter of the present invention can provide either a non-atomizing "lacing" spray pattern or the usual broad spray pattern for completely covering an area being coated, with the broad spray pattern being variable between the extremes of a low pressure, non-atomizing spatter and a high pressure, atomizing mist. In comparison, in a first embodiment shown in the abandoned application, the spray nozzle can only provide the lacing spray pattern, while in a second embodiment the spray nozzle can only produce the variable broad spray pattern. Although a third embodiment in the abandoned application discloses a spray nozzle which can achieve both the lacing and broad spray patterns, conversion of the spray nozzle between the patterns is inconvenient and messy. A rubber washer or the like must be inserted or removed from a component of the spray nozzle each time a broad or lacing spray pattern, respectively, is desired. Furthermore, the washers must be frequently replaced because of the degenerative effect that paint has on such washers. In addition, if the need exists for only a lacing spray pattern, only one of the two components of the improved spray nozzle need be purchased, with the purchaser having the option to buy the second component if the broad spray pattern is needed. However, in the third embodiment discussed above, both components of the spray nozzle must be purchased even if only the lacing spray pattern is needed.
Another advantage of the improved spray nozzle of the present invention over the spray nozzle disclosed in the previous abandoned application is that the nozzle of the present invention may be mounted on approximately 70% of existing spray guns without modification of the discharge control needle valve thereof. This feature is achieved by the improved design of the improved spray nozzle over the prior art nozzles described above, which are limited with respect to the number of different spray guns on which they may be mounted.
There is no liquid spray nozzle adapter for spray guns of which I am aware which provides a variety of spray patterns by simple adjustment or removal of a component of the spray nozzle, which eliminates or materially reduces the amount of atomization of the liquid during a spraying operation, which enables liquids of various viscosities to be sprayed without changing the viscosity of the liquid, and which is compatible with a majority of the spray guns now in existence.